Some ‘improved cookstoves’ may emit more pollution than traditional mud cookstoves

The first real-world, head-to-head comparison of “improved cookstoves” (ICs) and traditional mud stoves has found that some ICs may at times emit more of the worrisome “black carbon,” or soot, particles that are linked to serious health and environmental concerns than traditional mud stoves or open-cook fires. The report, which raises concerns about the leading hope as a clean cooking technology in the developing world, appears in ACS’ journal Environmental Science & Technology.

Abhishek Kar, Hafeez Rehman, Jennifer Burney and colleagues explain that hundreds of millions of people in developing countries in South Asia, Africa and South America are exposed to soot from mud stoves and 3-stone fires used for cooking, heating and light. The particles can be inhaled deeply into the lungs and have been linked to health problems similar to those associated with cigarette smoking. In addition, black soot released into the atmosphere is a major factor in global warming. Aid agencies and governments have been seeking replacements for traditional cookstoves and fires to remedy those problems, with ICs as one of the leading hopes. Until now, however, there have been little real-world data on the actual performance of ICs — which have features like enhanced air flow and a battery-powered fan to burn wood and other fuel more cleanly.

The researchers measured black carbon emissions from five IC models and traditional mud stoves. They did the test in real homes as part of Project Surya, which quantifies the impacts of cleaner cooking technologies in a village in India. Forced draft stoves burned cleaner than any other IC. However, black carbon concentrations from all ICs varied significantly, even for the same stove from one day to the next. Surprisingly, some natural draft stoves occasionally emitted more black carbon than the traditional mud cookstove.

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The researchers acknowledge funding from private donors, the National Science Foundation, the Swedish International Development Agency, the United Nations Environment Programme, the Vetlesen Foundation and the Alderson Foundation.

The American Chemical Society is a nonprofit organization chartered by the U.S. Congress. With more than 164,000 members, ACS is the world’s largest scientific society and a global leader in providing access to chemistry-related research through its multiple databases, peer-reviewed journals and scientific conferences. Its main offices are in Washington, D.C., and Columbus, Ohio.

Abstract
Use of improved (biomass) cookstoves (ICs) has been widely proposed as a Black Carbon (BC) mitigation measure with significant climate and health benefits. ICs encompass a range of technologies, including natural draft (ND) stoves, which feature structural modifications to enhance air flow, and forced draft (FD) stoves, which additionally employ an external fan to force air into the combustion chamber. We present here, under Project Surya, the first real-time in situ Black Carbon (BC) concentration measurements from five commercial ICs and a traditional (mud) cookstove for comparison.

These experiments reveal four significant findings about the tested stoves. First, FD stoves emerge as the superior IC technology, reducing plume zone BC concentration by a factor of 4 (compared to 1.5 for ND). Indoor cooking-time BC concentrations, which varied from 50 to 1000 μg m–3 for the traditional mud cookstove, were reduced to 5–100 μg m–3 by the top-performing FD stove. Second, BC reductions from IC models in the same technology category vary significantly: for example, some ND models occasionally emit more BC than a traditional cookstove. Within the ND class, only microgasification stoves were effective in reducing BC.

Third, BC concentration varies significantly for repeated cooking cycles with same stove (standard deviation up to 50% of mean concentration) even in a standardized setup, highlighting inherent uncertainties in cookstove performance. Fourth, use of mixed fuel (reflective of local practices) increases plume zone BC concentration (compared to hardwood) by a factor of 2 to 3 across ICs.

Seems very strange that they wouldn’t instead note efficiency in terms of fuel use. Fragile ecosystems are being destroyed by this, and use of charcol. If these can for example boil a given amount of water while using less wood or charcol, that would seem to justify their use. BC is not the issue.

Now if only there was a technology somewhere that allowed you to burn fuel efficiently at a central location and convert it into clean electricity, that way you could eliminate soot in the home altogether. Oh well, some day maybe.

From the article: “Two billion people, one-third of the people on Earth, are caught in a time warp, with no access to modern energy.” says Lakshman Guruswami
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And so, the modern “Green” dilemma and the world’s choice.
Follow the edicts of the “concerned” and condemn your own population; not a difficult choice for the less developed nations to make.
All that’s left for them to do is to try to pick the pockets of the developed world.

Willis needs to weigh in on this one but, if memory serves, the point of the eco-friendly cook stove is increased efficiency. If the fuel is efficiently burned there would be decreased consumption of limited resources and decreased emissions.

“Aid agencies and governments have been seeking replacements for traditional cookstoves and fires… with ICs as one of the leading hopes… which have features like enhanced air flow and a battery-powered fan to burn wood and other fuel more cleanly.”

Battery-powered fans… ??? for poor people?. Who came up with that one? Batteries are expensive, short lived, a hassle, can explode if heated, and have a chemical waste issue. Someone has not thought this through thoroughly… Why not a battery powered electric hot plate then… that should be equally successful for them and “greener” too. sarc.

The Enviros should go to Trivandrum during Pongala and set these people straight.
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Rice, coconut and jaggery are brought by women devotees along with round earthen pots for cooking. Women participating in the Pongala squat on roads, bylanes, footpaths and shop fronts in a radius of several kilometres around the temple to cook the mixture of rice, jaggery and coconut in earthen pots that is offered to the goddess seeking divine blessings.

The annual Pongala festival of Attukal Bhagavathi temple, has been entered in the Guinness Book of World Records as the largest congregation of women in the world. The festival draws over 2.5 million women on a single day in March to perform the Pongala ritual, and has been a center of attraction for devotees as well as tourists who visit Trivandrum during this season
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en.wikipedia.org/wiki/Pongala

The people in those photographs above can’t afford ICs, never mind the ones that require batteries, because they can’t afford batteries either. What they need is electricity, pumped out from nice big generation plants.

I’d assume a centralized communal cooking area in villages with rocket stoves would be both the most efficient, lowest on soot and please lefty sensibilities at the same time.
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Communal cooking? Come on!
You live in a neighborhood, right?
You like the idea- you try it.

It seems to me that we learned in the 1950s backyard incinerator debacle in Los Angeles County that the “black carbon” in the air was also known as “activated charcoal” that trapped the crap from the Fontana steel mills and the El Segundo Butadiene plants (for examples–there were a lot of others) and carried it to the ground instead of poisoning us.

We also need to ban candles. Why? CO2 of course.!
Flickering electric candles with mercury are OK, though.
Try forcing that one on billions of dogmatic devotees…
In wishing Peace and Love to the planet…
I’m going to go light a candle…
…and put more logs in the wood stove…
…and fire up the bar-bee-Q for lunch….

I’d assume a centralized communal cooking area in villages with rocket stoves would be both the most efficient, lowest on soot and please lefty sensibilities at the same time.
__________________________
Communal cooking? Come on!
You live in a neighborhood, right?
You like the idea- you try it.
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I think Luther under estimates the competition for food.

One of the biggest sources of pollution in the Mexico City area is propane from stoves with badly-fitted connectors. No matter what it is, it can be a problem if there’s enough of it and humans can get their hands on it.

solar ovenhttp://solarovens.net/
a one-time cost. can be used, with education, to purify water to potability.
ideally, an acceptable, well-performing model would be produced ‘locally,’ rather than coming from China.
A lot of the locales that depend on burning wood have what it takes to adapt to this style of cooking: people, time, and a diet that is not overly dependent on foods like seafood and mayo that spoil if the heat is not quite hot enough.

-someone noted that humans have been burning wood as a heat and cooking source for eons. Yes. We have also denuded great portions of land.

Until now, however, there have been little real-world data on the actual performance of ICs — which have features like enhanced air flow and a battery-powered fan to burn wood and other fuel more cleanly.

Use the batteries from all those unsold Chebby Volts. Since they self-combust, there’ll be no need to use charcoal or any other free-range fuel…

As far as I can tell, either they eat from their unsanitary old cooking wear, or they use the much more sanitary cooking wear that emits soot, which may be causing “global warming”. Hmm… I’d go with sanitary cooking wear.

Wow, I”m a little surprised at the variety of comments here. Several people have chimed in about the batteries. Those little fans can be driven by a very small amount of electricity, and that could easily be supplied by a couple of AA rechargable batteries. A charge might last a week or two, and a simple exchange system with newly charged batteries from a solar panel or two (or any other source of electricity) could provide easy money for a local entrepreneur.

These people are poor, but they are not completely without resources. They do have access to cheap electric devices. A forced air cooker is by far the most efficient way to burn wood scraps. While natural updraft gasifiers also work, they are not as quick or as clean as a forced air stove.

If I were in an area where I might have to scrounge for sticks and twigs to burn to cook my supper, I’d damn sure want to use a fan to blow on the burning coals. I might choose to make my own adobe cooker, but I’d give it some help. If I had a wife who wanted a nice, clean stove to impress the neighbors…

The black soot issue is less important in my mind than reducing the amount of resources the locals are required to obtain every day to cook with. Still, in many areas of the world, lung disease from breathing in smoke and soot from the cooking fires is a major problem. I’ve seen pictures of their homes, with scorch marks in one corner where they build an open fire for cooking. It’s no wonder that they have breathing problems. The science of chimneys has been worked out for centuries. With a proper chimney, a “mud stove” is not a danger to the occupants of the room. We need to spread knowledge more than anything. Knowledge of how to make functioning chimneys, wood-stoves that heat the home without smoking it out, etc.

Giving them gadgets, no matter how nice, isn’t going to make their lives better if they don’t understand why the gadgets work – why they are needed.

It is going to take many, many years of very hard work with large amounts of monetary investment before the “three-brick, open-fire” method of cooking hot meals is anywhere near being changed for the great proportion of humanity who regularly prepare food in this way.
I grew up on a farm near Luanshya, a dying copper mining town in Zambia’s Copperbelt Province; the Roan Antelope Mine is now Chinese-owned and employs few Zambians. http://www.zambia-travel-guide.com/bradt_guide.asp?bradt=405
Unemployment is rife with most residents of Luanshya being out of work but living in houses which have an electricity supply from the Kariba Gorge project on the Zambezi River. Their only problem is that they cannot afford to pay for the power so they cook over open fires in the back yard. Millions more Zambians live very far away from any electricity supply and all rely on open fires for cooking. Even urban residents consider two hours a day of water supply to be a bonus, just don’t try drinking it! Everone else goes to a stream or river for their water supplies.
Few, if any, of the many Zambians I used to know (most have succumbed to the many endemic diseases) could afford anything like a ‘rocket stove’ or other contraption. They are simply too poor.
Zambia’s economic prospects might be looking up but the <'wapamwamba' (the wealthy elite) in Government ensure that little or nothing in the way if benefits ever gets down to the poorer sections of the nation. It might be of interest to the ‘greenies’ of the more developed parts of the world that this reliance on wood and charcoal for cooking in Zambia has had an effect on the local climate. It rains less now. There’s not vast areas of mature miombo forest pumping large quantities of water into the air any longer. The 70′ tall trees have all gone from most of the entire Province.

“The particles can be inhaled deeply into the lungs and have been linked to health problems similar to those associated with cigarette smoking.”

Love this line… it should read the reverse…. smoking all smoking results in inhaling soot which leads to all the same problems. They can’t seem to grasp the reality that cigarette smoke isn’t much different from most other types of smoke natural or “unnatural”.

Communal cooking? Come on!
You live in a neighborhood, right?
You like the idea- you try it.

Ah yes, memories of the campus dorms, with a “communal” cooking area with some cabinets, a sink, a small refrigerator, and a four-burner cooktop. I remember seeing someone actually using a burner, once. And the refrigerator? Seemed to be where fungus went to die from starvation.

I see the whole ImprovedCooker issue as nothing more than a bandaid on a much bigger issue, and a symptom of people not being able to see the real problems at hand. Pointman’s got half way there:

The people in those photographs above can’t afford ICs, never mind the ones that require batteries, because they can’t afford batteries either. What they need is electricity, pumped out from nice big generation plants.

I’ll complete the analysis for him.

The real problem lurking behind the cook fire problem is lack of developement and lack of electrification to these areas of the world. Hook up these [presently] poor people to a reliable electrical grid – even if it happens to be powered by local ‘evil coal’ as a one generation expedient – and they will start to be able to address a whole array of other issues that piddly little biomass fueled cookers will NEVER be able to address: poverty, lack of education, lack of healthcare, lack of adequate housing, lack of, lack of, lack of… All of these lacks can all be addressed by abundance of reliable and affordable electrical power, without that none of them can be addressed.
Access to affordable electricity allows people to start to solve their own problems – like being poor. Hans Rosling, a Professor of International Health at the Karolinska Institute, has a wonderful talk at TED that illustrates an intelligent way to think about this issue and much more entertaining than me.

“Thank you steel mill! Thank you industrialization! Thank you power station! Thank you chemical processing industry that gave us time to read books!”
Of course certain types will never go for this idea, mostly in the fully industrialized West and many from Sweden ironically, this is because to allow the undeveloped poor to be allowed access to the electricity that will liberate them enough to be able to say no to what the well meaning, well intentioned elite in the West have in mind for them – which seems to yet anther kind of social experiment at someone else’s expense.
Make no doubt about it the ImprovedCooker, at it’s heart, is really nothing more than an instrument of social control sprung from the subconscious, and lack of foresight of a group of people who ought to know better as a means to keep people in the undeveloped world, undeveloped, and I do mean that in the very human sense that we mean that in the developed world: culturally creative, fully educated, politically empowered, and fully able to choose their own destinies.
Oh, and by the way, the market will sort out which sort of IC is the best bandaid to use for the moment, that is if the bad designs are allowed to fail properly and don’t become some kind of a UN mandate.

Wow, I”m a little surprised at the variety of comments here. Several people have chimed in about the batteries. Those little fans can be driven by a very small amount of electricity, and that could easily be supplied by a couple of AA rechargable batteries. A charge might last a week or two, and a simple exchange system with newly charged batteries from a solar panel or two (or any other source of electricity) could provide easy money for a local entrepreneur.

These people are poor, but they are not completely without resources. They do have access to cheap electric devices. A forced air cooker is by far the most efficient way to burn wood scraps.

I suggest you do a test to confirm your assumption that the batteries will last that long.
I suspect based on my experience that the operational lifetime for a small fan on battery power with a couple AA batteries would be measured in minutes rather than hours of useful power.

I wonder if the guys who designed these magic stoves realize that humans have been using hand operated bellows to increase heat in fires for a few thousand years. Instead of trying to get these poor folks to use their magic stove, maybe a $2.00 kit of materials to build a bellows (small piece of canvas and some tacks), would be a better investment.

…
These people are poor, but they are not completely without resources. They do have access to cheap electric devices. A forced air cooker is by far the most efficient way to burn wood scraps. While natural updraft gasifiers also work, they are not as quick or as clean as a forced air stove.

If I were in an area where I might have to scrounge for sticks and twigs to burn to cook my supper, I’d damn sure want to use a fan to blow on the burning coals. I might choose to make my own adobe cooker, but I’d give it some help. If I had a wife who wanted a nice, clean stove to impress the neighbors…
…

Have our modern monkey brains already forgotten about the ancient creation known as bellows? If they wanted forced air combustion then they could easily have it, without batteries or little electric fans. That they have apparently decided not to use easily-obtainable forced air combustion for cooking should be indicative of something, and that would not be “the ignorance of primitives”.

For something to think about, consider the cookware. Forced air combustion yields higher temperatures, thus it was considered necessary for metalworking. When using thin metal cookware, the heat is transferred quickly to the contents. But when using pottery, the heat is transferred more slowly. So burning fuel faster with higher temperature yields is wasteful, as the heat doesn’t penetrate faster. Slow steady heating, and gentle enough to avoid cracking and breaking, is what’s needed with traditional pottery cookware.

And while we have gotten used to readily-available inexpensive metal cookware, such are relatively recent, with scarcity of metal being the norm for societies both ancient and for some current ones as well. The heavy cast iron cookware of our grandparents and a bit earlier was quite an innovation. Cast iron, in case you haven’t had the experience of using it, does crack, it doesn’t like being heated quickly. So you wouldn’t want to use high-heat forced air combustion with it either.

In its 2007 report, the IPCC estimated for the first time the direct radiative forcing of black carbon from fossil fuel emissions at + 0.2 W/m2, and the radiative forcing of black carbon through its effect on the surface albedo of snow and ice at an additional + 0.1 W/m2.[87] More recent studies and public testimony by many of the same scientists cited in the IPCC’s report estimate that emissions from black carbon are the second largest contributor to global warming after carbon dioxide emissions, and that reducing these emissions may be the fastest strategy for slowing climate change.

While black carbon certainly warms the troposphere. It equally certainly cools the climate. This is because BC acts like a GHG in the other direction, scattering incoming solar radiation and returning some proportion out to space that would have otherwise reached the surface.

This picture is complicated by the hight of the BC in the atmosphere and, effects of other aerosols and effects on the hydrological cycle, but is supported by empirical studies of surface temperatures. How the IPCC could get this wrong baffles me.

I have to come out of woodwork on this one. Thanks for the important topic.

I see the promoters of various stoves popping up to publicise their favourite stoves For a complete look at what is going on in the world of stoves go to http://www.bioenergylists.org and read widely before accepting any producers claims. Most self-reported testing is quite biased.

Sticking to the very important topic of BC, BC nanoparticles have a very detrimental effect on human health, not so much organic carbon (OC). They even get into the red blood cells they are so small. Please do not try to minimise the effect just because some laugh at BC heating in the atmosphere (which is about 640 times greater per kg than CO2). BC circulates high in the atmosphere and can easily be measured inside a commercial aircraft with an aethalometer.

A very important, nay critical point: the stoves tested exhibited a large variation in emissions from test to test. In fact the method of assessment gave results with a high coefficient of variance (CoV). You will, well-meaning readers, have to understand that the tests method itself is responsible for a great deal of this variation, not necessarily the stove or fuel or operational method. The testing that is commonly done trying to capture emissions (various tests) are to say the least, inaccurate with systematic errors of 50% or more. The results of most testing shows that ‘fan stoves’ are much cleaner than most others. However that is just the stoves tested, it is not a statement that can be applied in principle fr all stoves. I have been working with natural draft stoves that are 99.9% cleaner than the baseline and a) they are not mentioned or tested, b) they do not require electricity and c) they can burn a wide variety of supposedly ‘dirty fuels’. It is not necesarily the fuels that are ‘dirty’ it is the stoves that are not designed properly to burn them. If you put diesel in a gasoline engine it makes a lot of smoke. Shall we blame the fuel?

Many poor people who have an electrical connection, often small and informal, cook with biomass. People without money do not cook with electricity. In South Africa 80% of people have at least some electricity. In Ulaanbaatar, Mongolia it is similar. Many in India have a small connection to the grid, even if tempermental. Running a fan stove is very inexpensive. There are battery powered fan stoves for campers in the US (campstove.com) but we are talking in India about rechargable batteries that can last for over a week (the BP pellet stove, well…ex-BP). If the power comes on, it charges, if not, no problem. Cooking on a fan stove burning pellets is very much like cooking on gas – highly controllable heat and rapid starting and much cheaper and safer than LPG. People like them a lot. We are trying to being them to the Eastern Cape in SA.

Natural draft stoves are also popular and there are very clean burning ones. However most stoves have significant drawbacks of one kind or another but are promoted by their enthusiast designers all the same. The best social fit is not always obvious to a backyard engineer – there are many factors affecting product choice.

Stoves are now available with thermoelectric generators (TEG) that will operate LED’s and charge cell phones (which many poor people have, BTW). TEG’s are becoming very cheap: <$3. There is even a pot with a USB port on the end of the handle.

The Sustainable Energy Technology And Research (SeTAR) Centre is promoting better, more accurate and flexible stove testing protocols so that this type of conversation leads ultimately to much better products, health and environment for all. The search for better products continues at all times.

Ah, the old “if a given solution can’t solve ALL problems, clearly it must not be able to solve ANY problems” routine.

I’ve been through the Mississippi region many times, often on recreational motorcycle rides that provide ample opportunity for casual observation of folks living off the main drags, and I’ve rarely seen people cooking for sustenance using dung. Have you?

Are you suggesting that the people living in the Mississippi region would be somehow better off WITHOUT access to affordable and constantly available electricity? Perhaps with no access to electricity, or only occasional access, or rolling blackouts–all those would be superior to the reliable electricity supplies they currently enjoy? That’s how you’d rather live, is it? How you’d rather your children grow up?

All this talk about fans a bellows, it appears that many people think that they are cooking tortillas and they are in a hurry. They’re not and they’re not. Some things are thin, some things are thick and some take time. They don’t need a forge. A small fire with hot over here and warm over there and keep the rice water warm on the rocks, all in good time. Anyone who has ever cooked a meal over a campfire knows you need all kinds of different heat.

Look at the image in this posting. One person (a child) is supervising a meal being cooked and the other person is boiling something. One meal will be ready all at the same time; whereas the rice (or whatever is being boiled) will be cold by the time the veggies are done which will also be cold once the flat-bread is done; and their socks will still be wet.

A lot of people don’t seem to get out much and are in a hurry all the time.

Ok, so the major issue (embarressment) is that whilst the EPA and most of the west promulgates a standard of 50 microgrammes of fine particulates (PM10) as a daily average for health in communities. Most people in underdeveloped countries are exposed to thousands of microgrammes per day due to a combination of poor cooking methods and natural background in desert areas. This is definately worth resolving, but It looks like the researchers have a couple of problems;
1) Their solution doesn’t consistently work
2) you cant’t get research money these days without including climate change in the grant application.

Electricity is of course the best way to go. Next would be gas, then oil, then high grade coal and lastly wood and dung…the dirtiest and environmentally most destructive fuels. This creative band-aid crap is annoying. With the money that we’re throwing at many places in the Third World, much more could have been done by now. It’s time to bypass the NGO idealists, the UN bureucracy and the layers of cleptocrats and to provide aid directly, without dirty local intermediaries.

Any one who thinks this ICS stuff is any good needs to read Stepehen’s article.

Stephen Brown says:
April 9, 2012 at 1:58 pm

A lot of you are behaving like idiots.

Most of the world is NOT LIKE the USA or Canada or the UK or France etc etc

Most people live in abject (power) poverty. Oh yes; an ICS would be great if you’re off camping; but it is pretty much naff all use if you have to
walk 5 miles to get water
spend 4 or 5 hours finding something to burn
do some basic subsistance farming (that’ll be another 4 or 5 hours)
hope some family member somewhere else in the world will remember to/be able to send a few $ (Rand/Kwacha/Ruppee/Nira – what have you) more than once a year so you can replace the importent things in life – baterries to power a cooker are NOT importent; school uniforms and text books are.

Not only does that dung/wood fire provide energy for cooking with it also provides HEAT for the shack. It can get damn cold at night in a lot of places where day time temps are in the 30C range. (Put your AC up to 35C – spend all days indoors – then turn it down to 15C – bloody cold is what that 15C is).

This is as bad as OXFAM used to be – send tractors to peasents who couldn’t GET deisal – never mind afford it. Everyone in the West in the 50s knew that sending tractors would solve the famines – right ?

AS another poster notes above; a cooking fire is damn all use if it can only cook one item at a time (try this at home folks; liver for just a week on 3 varietes of veg; odd scraps of meat; all cooked in just ONE pot; and now work out where to bake the bread).

How to solve the BC problem — get sustainable jobs into the area (old use of the word sustainable; not the new fangled political inverted meaning in use wrt power generation). When there is a little bit of money in the area get cheap power into the area and encourage small local industries – tailoring; brickmaking; etc etc. Get the tourists in.

When their standard lf living has increased enough then the BC problem will have auto magically disappeard,

My mother left Mississippi before I was born and rarely went back. I have visited there since (as a truck driver mostley) and it is pretty puch as I remembered it as a child except some of the streeets and roads are now paved. But I believe that central Mississippi my be the most economically and socially depressed area of its size in the Westerjn Hemisphere (thinking now of Detroit, I might have to re-think that.).

My children are all grown and are varying degrees of successful in spite of the best efforts of government.

I certainly would not have wanted them to grow up there–indeed I cut short a visit with them there when they were little because I did not want to expose them any more to what we saw.

And if you didn’t see views like thid article has at its head, you weren’t paying attention.

“Well, is it? Sheesh. I bet you have a PhD, too, doncha”

I have a BS in Managment from Golden Gate University. A BSBS, if you like. So no, I don’t have a PhD. As you can see–I can still observe reality as a result..

In the end any proposed solution that does not free the women of the developing world, from the highly unproductive *labor* and drugery of cooking over a fire, washing by hand, and spending much of their time cleaning their homes and getting food [and fuel] for their families is no solution at all. In the developed economies of the world this transition was accomplished generations ago, we now take it so completely for granted that we can no longer see what the real problem is.

The loss of human productivity, and waste of human potential that poverty and lack of developement represents, is in my mind the single greatest challange that faces humanity at present. All other challenges become much simpler when this issue is addressed. I’m saying this as someone who has lived with indigenous people [North American indigenous people] and spent two years living in a tipi, cooking every meal over a small wood fire, gathering wood, hauling water the whole nine yards. The idea of ‘living simply’ takes on a whole new kind of meaning when you are socked in for three or four days in a South Dakota blizzard and its snowing INSIDE the lodge whole time.

At the moment I happen to live in a town on the western bank of a long tidal river, very environmentally conscious, very progressive, very smart, very well educated population as a whole, [no fewer than five colleges and universities in the area for a population of some 100k], where one enterprising group of people created a business where people will come along and cart away your trash for a fee in grey plastic bins bungeed to a trailer towed behind a bicycle. They call themselves “The Pedal People.” They are very nice people, very well spoken, very earnest about what they do. They consider themselves to be doing a tremendously good thing for the world and for humanity. When I point out to them that what they have actually succeeded in doing is turning human beings back into DRAFT ANIMALS, they get a little upset. When I point out to them that they have also succeeded in setting civilzation back A THOUSAND YEARS, they get even more upset, I’m not sure why, this seems to be exactly what they set out to do in the first place.

Yet you never answered the question, Larry. Would the removal of regular, reliable electricity from the poor of Mississippi be a boon or bane for them? And if a boon, why deny it to the rest of the world’s poor? Is it REALLY better for the world’s poor to continue to subsist for cooking and heating fuel on dung rather than electricity? Because that’s what you advocated.

The more I read this, the angrier I get. On the one hand I see pictures and descriptions of people living in what I would call abject poverty, but not clearly showing any signs that they have a problem with that. Me thinking there is a problem with that (and I do) is one thing–them thinging there are more important things to worry about (and I fear that they may be right) is anothere.

On the other hand, I see people who see the problem as a trip to the wildeness at the end of the block, and the problems of preparing their freeze-dried packets of Beef Bourgoin with [anything but] Wild Rice with the bottled water they brought with them,

I am going to guess that the child is quite comforatbly operating his stove, while the device with the fires, LCD displays (how do they in the humidty?) might not be in his comfort zone. And will it keep hiom warm tonight the way the warm stones will? (I’ve actually been where I needed to heat rocks in the fire to keep my daughter warm through the cold night. I don’t see your Gaz stove doing that.

BTW, I’m also a big fan of thermo-electric devices and look forward to cheap IR photovoltaics that will harvest waste heat from just about anything you point them at. Back when I was in the turbine engine industry I worked for a company that, in the 1950’s, produced a thermo-electric generator device for backcountry use based upon the Seebeck Effect called a ‘Seegenator’ which consisted of about 4k chromel/alumel T/C junctions brazed to an aluminum tube, set a candle underneath the ‘chimney’ and you get enough DC to power a transistor radio. Very handy, you could store a candle right inside the chimney – never caught on.

All this talk about fans a bellows, it appears that many people think that they are cooking tortillas and they are in a hurry. They’re not and they’re not. Some things are thin, some things are thick and some take time. They don’t need a forge. A small fire with hot over here and warm over there and keep the rice water warm on the rocks, all in good time. Anyone who has ever cooked a meal over a campfire knows you need all kinds of different heat.

Not saying they “needed” a forge, just as many above are trying to point out, these people are not stupid. They know full well what they can afford and what is possible with their local resources. If they needed a forced draft for a hot fire, they have known how to do that for generations, using easily available local technology.

As you say, one of the most effecient ways to cook is to bring things to a boil then cover and let them simmer over a very small fire while they do other critically important jobs like gathering water, fuel for fires or tend to their herd or what ever other critical survival tasks are highest on their agenda at the moment.

I agree many of the commenters here simply have no grasp of true poverty, and subsistance living.

Just pointing out they are suggesting cadillac solutions for sharp stick problems.

The ‘Gasifier’ stove in the above video costs about $5 made locally by ‘tinsmiths’, and burns local grass stalks, or wood chips or other waste. 1kg grass replaces 3kg wood. Here’s a more detailed video of its structure and function. Turns organic fuel into methane, which is what flames at the top of the stove:

David in Georgia says:
April 9, 2012 at 1:44 pm
Wow, I”m a little surprised at the variety of comments here. Several people have chimed in about the batteries. Those little fans can be driven by a very small amount of electricity, and that could easily be supplied by a couple of AA rechargable batteries.

Never actually *lived* in a Third World country, have you, Dave? Chinese-made alkaline Double-As (if you can find them) usually last for about an hour in a small flashlight — if you want rechargeables, you’ll need both a reliable transformer and a friend in the US who won’t mind paying forty bucks to have DHL deliver five dollars worth of batteries…

How about providing these new third-world stoves with a bellows and a butt-pedal to power it? Rise up four inches and the spring-loaded bellows pops up and quickly “inhales”; sit down and the bellows gradually exhales. (The exhalation rate could be adjusted by twisting a valve on the end of the bellows.) A stove-tender might be able to build up a regular rhythm if the bellows also had a valve to adjust the inhalation rate.

If that approach didn’the work well, then maybe if a “bladder” or compressor tank were added the stove-tender could occasionally bounce up and down in a regular rhythm for ten seconds (say) to fill the bladder or tank, then relax for 30 seconds or so.

A metal tube would lead from the bellows to a port or air-hole on the stove, so this gadget could be an “aftermarket” add-on to existing stoves.

It is great that the discussion morphed into one on how the developed world has forced poverty onto these communities by acting like do-gooders while conspiring with the leadership.

I eventually figured out that most of what we “democrats” were pushing was actually some elitist totalitarian utopia that we dreamed up in our dreams, to solve a host of problems we manufactured in our nightmares.

no third-world country ever came to the U.N and said, ‘hey, do y’all know why our waterline has disappeared due to a 1 mm rise in the ocean lately? They never trekked off to the U.N. and said, ‘hey, breast-feeding is so over-rated – what do y’all do over there in the developed world? Formula? Hey, sounds great! Send us all you got!” They never strolled into the next U. N. meeting and said, “gee, harvesting seeds is just so much hassle – have y’all figured out a way to grow crops year after year without having to save seeds? Genetically modified crops where we have to rebuy seed year after year, instead of just saving the seeds from one year to plant the next? Wow, that totally solves a major problem for us!”

To my credit, when I mentioned a solar stove, I did mention that it ought to be followed by a plan to make these locally.

A decent solar oven is realtively expensive. But instead of the aide we do give, we ought to pour that money into giving away zillions of $100/piece solar ovens at no cost, and with basic directions. THen, when there is some critical mass of knowledgable users, developing local manufacturers, and our elistist educated developed world role morphing to a matter of supplying the decent glass (from China). Then, at some point, figuring out how to ‘source’ glass, metal, etc. as local as possible.

This builds trade networks, and builds wealth in the impoverished.

But don’t be fooled – our govts and the U.N. and such don’t really want to end poverty, in my humble opinion.

My crazy solar oven idea could be done by private charity and circumvent the intl NGO machines. As a private citizen, I have already donated money to private intl charities doing things I approve of.

“Electricity is of course the best way to go. Next would be gas, then oil, then high grade coal and lastly wood and dung…the dirtiest and environmentally most destructive fuels.”

++++++

Please understand that a fuel that ‘burns dirty’ is not necessarily ‘dirty’ at all. If a stove is not designed to burn a fuel (an open fire is not a stove) then one can expect a poor combustion efficiency. Coal has been demonised as ‘dirty’ meaning that coal fired power stations and household stoves emit a lot of smoke (PM). That is cherry picking. The cleanest natural draft (chimney) coal stoves currently available are so profoundly low in their emissions of PM that they are literally cleaning the ambient air that goes into them. The labelling of coal as ‘high quality’ has nothing to do with the quality per se. It has to do with rating the volatile content. If a coal has high volatiles (‘low quality’) it is far easier to light and burn cleanly, though most stoves don’t do that. But they could.

Lignite buring improved stoves are now burning so cleanly it is becomming difficult to measure the smoke mass even with sensitive instruments. Ulaanbaatar is the most heavily polluted capital in the world – largely caused by domestic coal stove emissions. This winter 72,000 new stoves were sold (subsidised) which is about 1/2 the need, and those stoves produce less than half of one per cent of the smoke emitted by the traditional (wood) stove in which coal is burned. You don’t put diesel in a wood stove and you don’t put coal in your car. The fuel, the stove and of course the pot operate as a system. Many so-called ‘dirty’ fuels burn very cleanly. Paraffin is often characterised as ‘smoky and dirty’ but it burns very well in a jet engine or any of the new stoves generation of paraffin stoves permitted in South Africa.

The variation in test data from these stoves could be moisture content in the fuel, patty a tad fresh, or if wood, the variation in which different wood burns is huge. Lining these stoves with refractory material would enhance the performance. If a fan is needed a wind up clock work is the best option, they have had wind up radios in Africa for years thanks to some very good altruism I think from an Englishman. Batteries are a no no it makes them poorer.

Best option for all western countries giving aid, tie it to a project and oversee it and build the dams and power stations and really help these people. The time from poverty to well being is very short if done right. Then the aid can be directed else where rather than have an ongoing night mare.

kbray in california@April 9, 2012 at 10:30 am has the right idea. Better the WWF, et al, buy and distribute portable nuke plants in and around densely populated areas. Cooking is only a minor issue without clean water and power. Physics will, like Darwin, always win out. That part that’s such a big topic on climate sites – thermodynamics. Without Harry Potter’s magic wand, it’s like using super glue to weld trains together.

And do it one nation at a time. If one has power plants operating then one will have stable governements, foundations for an economy and all the other things that actually allow them to solve their own problems.

An efficient stove that can be made locally and quickly out of a tin can is a much better solution for the third world. Tin cans are found worldwide. What is required is training. Unfortunately there is no profit in the device and thus it is unlikely to be promoted by aid organizations.

Anything that costs $$ and/or requires batteries is simply a waste of aid money to supply to the third world. It isn’t that they can’t learn technology. The problem is that there is no infastructure to support the technology, so minor problems quickly lead to failures and abandonment.

A tin can that can be quickly cut with a knife to function, then fueled with any biomass at hand, that saves fuel for a given amount of heat produced will be adopted because of the fuel savings, not because of the smoke reduction. If you live anywhere there are mosquitoes, it is standard to gather up the fallen palm fronds and leaves and burn them to make smoke. Malaria and dengue are real problems that affect people today.

I stand corrected, partially, in that I agree that coal-burning technology on an industrial scale has come a long way in reducing emissions of pollutants. I imagine practical and economic improvements are still possible and the benefits of affordable fuel outweigh those of fuel poverty. At a consumer level, though, the case for coal appears to be harder to make. There seem to be a number of advanced home units on the US market, but they are expensive and the improved stoves don’t appear to offer a significant difference. Unlike the EPA, I don’t count CO2 as a pollutant, but CO in an enclosed environment, particulate matters and sulfur are problematic.

The only info I was able to find on Ulaanbataar and “improved stoves” was a 2005 report whose conclusions are not a glowing recommendation. Analysing reports like this one is not in my bag of skill sets, but I wonder whether the negative assessment is due to overly high standards set by activist agencies, inferior technology of the “improved stoves” supplied for the study, ones possibly designed to be affordable, the researchers’ concerns and politics over CO2 and greenhouse gases and lack of comparisons with the alternative…fuel poverty and the environmental and health effects of chronic exposure to cold and the burning of dung in an open fire pit, which I imagine would have been the norm among herders in tree-poor environments. The bottom line, I think, is that coal is an improvement on wood and raises dismal life expectancy levels among the fuel-poor. I have my doubts, though, that it’s an ideal fuel for individual home use on a mass scale, in cities and in the West, even with the current types of stove technologies. Perhaps you can take a peek at the article; I’m not sure if these are the stoves you mention, as the report is from 2005. I pasted the abstract below, but you’ll have to search the article its it by title on the site I’ve cited, as the URL is ridiculously long and would bugger-up the page here:

Ulaanbaatar, Mongolia, is the coldest capital city in the world, with average winter low temperatures of –20° Celsius. Many families there live in gers, traditional
Mongolian dwellings consisting of a wooden frame beneath several layers of wool
felt. In the ger districts of Ulaanbaatar, cooking and heating energy is provided
through indoor coal combustion in metal stoves with chimneys, and in wintertime,
such stoves may be in use both day and night. Over the last several years, new stove
designs with improved fuel efficiencies have been introduced into many homes.
To test the impact of the improved stoves on indoor air quality, 24-hour monitoring of
particulate matter (PM) and carbon monoxide (CO) was done in 65 Mongolian gers.
The primary analyses focused on 58 households, 20 with original (or traditional-type)
stoves, 18 with the improved stove type TT-03, and 20 with the improved stove type
G2-2000.
In addition to indoor pollutant concentrations, information on other relevant factors
was collected, which included home sizes, indoor and outdoor temperatures, age of
stove in use, amount of fuel used and number of refuelings, position of monitors
relative to chimneys, and number of cigarettes smoked in the home. Analysis of
variance showed that these factors did not differ significantly by stove type except
that traditional stoves tended to be older than improved stoves. Multivariate
regression methods were used to test for statistically significantly different indoor PM
and CO concentrations between homes with different stove types while controlling for
selected characteristics.
In homes with all stove types, the average level of indoor concentrations of PM and
CO exceeded Mongolian national standards for 24-hour concentrations, and in the
case of PM, the excess exposure was large. The Mongolian national standard for 24-
hour CO is 2.6 parts per million (ppm), and the average of 24-hour CO concentrations
over all households was 9.5 ppm. The Mongolian national standard for 24-hour
average total suspended particles is 150–200 micrograms per cubic meter (μg/m3),
and the average 24-hour observed PM concentration was 730 μg/m3 over all
households. The indoor pollutant levels also exceeded air quality guidelines set by the
World Health Organization and standards set by the U.S. Environmental Protection
Agency.
For both PM and CO, no statistically significant decrease was found in homes with
improved stoves for 24-hour average concentrations, 15-minute maximum
concentrations, or 2-hour averages during the morning refueling period. However,
there was a nonsignificant trend toward lower CO levels with improved stoves, which
would be consistent with an improvement in combustion.
Although the number of refuelings during the day did not vary by stove type, coal
consumption was significantly lower in households with G2-2000 and TT-03 stoves
than in households with unimproved stoves, with an average decrease of 5 kilograms
per day seen in homes with improved stoves.*

Crispin Pemberton-Pigott, SeTAR Centre, Univ of Johannesburg says:
April 10, 2012 at 12:34 am
Please understand that a fuel that ‘burns dirty’ is not necessarily ‘dirty’ at all.

+++++++++
good post, worth reading. it is the technology used, not the fuel that makes something “dirty”.

Unless of course you measure CO2. Then coal is inherently dirty and oil and gas is clean, and CO2 taxes can be used to increase the profits of oil and gas companies at the expense of coal companies. So if you are a billionaire buy oil stocks in venuezula and promote carbon taxes via your man in the white house. Shoot down the XL pipeline as this would reduce your profits.

>I stand corrected, partially, in that I agree that coal-burning technology on an industrial scale has come a long way in reducing emissions of pollutants.

Actually it is the domestic stove with which I have had so much success. There is a set of papers on how it was done and a complete set of drawings for one of the stoves developed – the GTZ 7 series at the website http://www.newdawnengineering.com in the LIBRARY then STOVES.

The PM and CO emissions from the newest stoves are lower than even the most modern power plant with static precipitators. All that I wrote above was about small stoves, not big burners.

>At a consumer level, though, the case for coal appears to be harder to make.

We have finished making it. Extremely clean burning stoves (4 different ones plus the GTZ 7) are available heavily subsidised in UB.

>…a number of advanced home units on the US market,

The US is quote far behind on this I think in part because there is no strong need to worry about them.

>The only info I was able to find on Ulaanbataar and “improved stoves” was a 2005 report whose conclusions are not a glowing recommendation

This started to get onto the right footing in late 2007. The first lesson was to show that the fuel can be burned exceedingly cleanly, against all expectation as it had been defined as ‘dirty’ by so many people who did not know how to burn it. Incidentally the coal they use has high hydrogen and low carbon. Heh heh. So much for being ‘dirty’.

>…but I wonder whether the negative assessment is due to overly high standards set by activist agencies, inferior technology of the “improved stoves” supplied for the study, ones possibly designed to be affordable, the researchers’ concerns and politics over CO2 and greenhouse gases and lack of comparisons with the alternative

The real problem was no one had ever seen or used a really clean burning coal stove. Simple as that. The demonstration of several downdraft stoves with 1/2000th of the emissions was the starting point. It took 2-1/2 years to get people’s heads turned around. Some of them at least. Now MCC is putting massive resources into getting the traditional stoves replaced. The reduction in PM for the main product is 99.94% over the baseline as traditionally operated. We call them ‘Three 9’s stoves’. There are 5 which are in that Three 9’s category. No subsidy for products that are less than an 80% reduction.

>Perhaps you can take a peek at the article

I am familiar with the article. What you need to see is the AMHIB Report produce by the much maligned WB that pulled off this extraordinary improvement. The full name is, “Urban Air Quality Analysis of Ulaanbaatar: Final Report of the Air Monitoring and Health Impact Baseline Study by the World Bank”

It provided a key detail from a times series analysis of smoke which was that the emissions on ignition are nearly all the smoke that will be produced by the stove. By concentrating on ignition emission reduction, we were able to profoundly reduce the PM2.5 production. The coal is a wet lignite and burns very cleanly because of the high H2 content. The combustion trick is to use a long residence time for the cracking of the evolved gases. Basically top lit and cross draft stoves are good at this. I will see what happens with the best downdraft fires. The SeTAR Centre is concentrating on that at the moment.

So Ferd B: young supposedly low quality coals with oil and water and so on are low in Carbon! Ha ha! it’s funny because they have been dismissed on the basis that they do not burn well in a power station designed to burn hard dry coal. Well…..duh! No kidding.

In the stove world, UB is a signal success and was achieved by quite a number of players local and not, coordinated by the local WB staff and the energy office in BJ, China. The Asian Dev Bank supplied crucial funding in 2010 to construct and run a SeTAR Centre testing lab in UB so product developers could get free design advice and testing. It is an approach that can work in China with similar results. One of the fun parts is overthrowing the dominant paradigm and setting a whole industry on a new footing of proper science and engineering. The prospect of repeating that is why I hang out here at WUWT.

Oh, the good stoves save 50% of fuel as well because they burn the smoke and have much better heat exchangers. That will save the city’s poor something like $25 million in fuel purchases per year.

Brian H says:
April 9, 2012 at 9:37 pm
Bill;
Not to mention a handy 110V 60Hz socket to plug the transformer into.

True dat, Brian. I run my laptop from a nice, compact converter/transformer with two ganged adapters — smoothes 220/240 at wildly-varying frequencies quite well — and it only cost what the average Somalian makes in a month.

One of our ops guys can’t quite grasp the fact that he isn’t in Kansas anymore — he popped an adapter over the plug of a 110/120 printer and stuck it into a 220/240 socket, with predictable results. His callsign was changed from “Tuffy” to “Sparky” by acclimation…

Nancy Hughes, founder of StoveTeam International
I have just returned from Mexico and Honduras doing Kitchen Performance Testing on the Ecocina rocket stove that is produced in local factories. it is a safe, affordable, portable stove made locally in Central America and Mexico. Testing such as the Kitchen Performance Test, Controlled Cooking Test and Water Boiling Test are being developed to ensure that all “fuel-efficient stoves” really are fuel efficient, safe and affordable. The initiative started by the EPA Partnership for Clean Indoor Air and the Global Alliance for Clean Cookstoves will assist local developers in knowing exactly what they are providing in the way of benefits. Check our website at http://www.stoveteam.org and you can see the results of our development of portable, safe, fuel-efficient rocket stoves.

Thanks for this rather stunning info. The numbers you are rolling off would be unbelievable, except that I took a peek earlier at your impressive background. I’ll be looking more closely at your suggested sources and your site.

This is actually a topic that’s near and dear to me. I grew up with coal as a kid in Prague in the 60s and have a love-hate relationship with it. I hated the chore of lugging buckets of the stuff from the cavernous basement with the single light bulb and the long shadows, three flights up, cleaning out the ashes with down-drafts blowing in my face, getting up at night to load and stoke, waking on a cold morning and waiting for Dad to get the stove going for our breakfast. Some of my classmates lived in the newer projects for Party members and “academicians,” and boasted of central heating (steam from coal-heated boilers) and gas ranges (gas from coke production). But some of my best memories include lounging around our coal stove on bitterly cold nights, heating water for linden tea and slowly crisping orange peels on the stove top for scent.

We had two stoves; one in the kitchen, which included a bake oven and a warming compartment, and one in the living room, with the smoke pipe going through my parents’ bedroom. This was in the ration days when we were stuck with lignite during the shortages, black coal lumps and briquettes most of the time and occasionally coke, which made our stove glow a bright red with the lights off…which happened from time to time due to blackouts. There was always a bit of smoke, a smell I can still “taste” and when both stoves were going at full blast, we felt woozy, from the heat and possibly the CO as well. There was black soot all over the city staining everything and rust-coloured ashes strewn over the sidewalks in lieu of road ice. The bitter-sweet “romance” of the coal stove days.

Here, in Ontario, I have yet to see a single coal stove, although there are plenty of wood ones…something that puzzled me because coal, for all its black dust I hated, is so much more efficient. I’ve dabbled in brick masonry and historical masonry structures, taught the subject at a technical school and built several fireplaces with a colleague, including a Rumford. My friend’s a bit of a math wiz and we modified smoke chambers, played with dampers and constructed angled and spiraling smokestacks which improved efficiency. Recently I co-edited and illustrated the first textbook on Canadian brick and stone masonry, after a hiatus from the trade, and was disappointed to see that not much has changed in masonry fireplaces which are pretty, but as inefficient as ever. Not that anyone is building traditional ones anymore; almost every builder is now specifying metal liners.

The stuff you’re telling me, the efficiency levels, fuel savings, cleanliness and low unit costs are breath-taking, truly revolutionary, if people really thought about it. I have yet to look at the details of your stoves and I’m now wondering whether it’s feasible and practicable to design masonry versions suitable for local installation, combining inexpensive manufactured parts and local masonry skills. Such, I’m thinking, may be useful as more permanent installations in communal kitchens and food service enterprises such as small artisan bakeries, or as upgrades for greater safety and better appearance in houses. The problem I can see is in ensuring quality construction to specs and acquiring good refractory clays and firebrick, as Portland cement mortars and structural clay bricks cannot be used safely.

This is a fascinating and honourable area you’re working in, Crispin. As someone who’s grown up around the struggle for heat and felt the bite of fuel scarcity from time to time, I’m ever-sensitive to this topic. It affronts me, as I now sit in an over-heated house, to know that people all over the world are still scrounging for scraps of fuel and choking on smoke and fumes while trying to stay warm or to prepare a meager dinner. Do remember me if you folks are looking at masonry in any way, as I and my contacts may be able to suggest a thing or two.

I see the guys are using red clay bricks shaped like solid fire bricks and a cement-based mortar, rather than refractory clay, as we’d spec in Canada. They’re keeping the joints tight enough, as required for a fire box, at about 3 mm. For you regular non-mason mortals who are still reading this, tight joints (i.e., the spaces between the units) on a fire box structure reduce heat loss through the joints.

I do fret a tad about the durability of the regular masonry unit (unless your fire clays in SA are red) and have recurring nightmares about structural mortars under high and prolonged heat. Cement mortar has a good bond and is strong enough, but if you are not going to use firebrick and refractory clay, do you require Portland cement in the mortar mix? Portland provides for greater compressive strength, but it is brittle, depending on the type. Going by the pics, and guessing from the colour, it looks like you’re using Type M mortar, the type with the highest cement concentration, possibly from a bag of pre-mix. Not the type I’d use unless I’m building a reinforced c-block foundation. Have you tested lime-sand (Type K) mortar? It’s the weakest in terms of load bearing capacities, but has superior plasticity and some flexibility, and “heals” well. Differential expansion and contraction rates between the brick and the Portland in mortar mix as the stove heats and cools may be of concern and a more flexible mortar…if you can’t use refractory materials…might help. Also, locally available clean sand and slaked lime ,ay be economically more practical.

I’m intrigued by the pumice stones for insulation. With refractory units and mortar we merely parge the back and a clearance between 150 mm to 300 mm is more than sufficient, but heat loss through the walls in a fire place or an oven, in Canada, translates as room warming which is welcome. Are pumice stones widely available and cheap? What about using similarly-sized brick or c-block chips from wasted units? I also note that the inside gets parged, but I don’t know enough about the structure to figure out whether that part is the equivalent of the smoke chamber or the fire box.

And hurray for the superior London trowel I see in the pic! Here masons tend to use the broad Philadephia pattern one, the “glorified shovel,” on everything. The guys need safety boots, though; one of the guys has managed to keep his sneakers a pristine white by some miracle. And a 1200 mm level to help as a straight edge would be nice too.

Very, very, interesting stuff all in all. I’ll be reading up more on it.

Once again I read of various “improved” cooking fire devices that are too fancy, too costly (including because they are attractive to steal – look at that highly-fabricated overly-complex one the second photo). One even requires buying batteries to operate it! (Which isn’t even suitable for hikers here – batteries are heavy. Even thermo-electric junction fans are costly (powered by heat from the stove, won’t work on a clay stove).)

I hope there are principles of creating a “draft” to enhance combustion and propel gases and soot away from users. Those principles might be simple and teachable so poor people could make their own of local materials with minimal tools (like the first photo which appears to be mud, or this efficient one: http://www.stoveteam.org/solution). Perhaps supplemented by something like a galvanized steel chimney pipe as height is harder to make of mud, though is done. Even the Vesto stove is apparently economical to make (though still quite a bit of money for poor people it appears to include a cooking pot at the top and is made of stainless steel for longer life: http://www.newdawnengineering.com/website/stove/singlestove/vesto/). Poor people tend to have time not money (“David in Georgia” fails to actually understand their situation).

The variability of fuel is mentioned – it is a major cost in many poor areas, especially very dry climates. I presume varying the chimney restriction might help (IIRC commonly done with wood heaters here, “David in Georgia” seems to be suggesting that, the Vesto does it by varying air intake at the bottom). A raised stove with pedal-driven fan may we workable, leaves hands free, uses strength of legs, but not as portable as foot-operated bellows.

As for reducing CAGW, well – “I’m from Missouri” on whether or not soot is actually a problem.

Elimination of forests to provide fuel is in major part a result of not owning the resource (owners preserve it, replanting and husbanding the new crop). Hernando de Soto has pointed out the importance of ownership to improving the lot of poor people, and the necessity of law and order to protect property rights.

Poor people often need portability, to move to where food and fuel are, and escape when some tyrannical regime abuses them. “boston12gs” overlooks that – electricity supply cannot happen without a stable society, as there is no incentive to maintain the system, and various combatents will destroy it (if it ever gets built – corrupt officials will build shoddy if at all).

I give credit to an operation called “World Vision”, whose solicitation of funds is for specific things that can be purchased for a poor person, ranging from a breeding animal to a water well. Specific things that would actually work for the recipient, clearly understandable by the prospective donor.
(I know nothing of the outfit otherwise, though the last catalogue I saw was jumbled and I shudder at the cost of the catalogue they put into each newspaper.)

Of course the broader picture is what cooking does – improve digestibility of food. Won’t that reduce the energy cost to each individual of digesting food? That is, the net energy gain from the food is greater due to the use of energy outside the body. Marvelous thing, controlled fire. (But has to be handled well – philosopher Ayn Rand liked Francis Bacon’s point “Nature, to be commanded, must be obeyed.”)

Keith Sketchley says:
April 14, 2012 at 10:17 am
…
Of course the broader picture is what cooking does – improve digestibility of food. Won’t that reduce the energy cost to each individual of digesting food?

Interesting point; in addition, “digestibility” means extracting maximum energy from the amount of intake, instead of having to hunt/gather a larger quantity — which also costs energy to accomplish. It thus reduces the demands of humans on the environment to supply edible fuel, therefore.